community[minor]: SQLDatabase Add fetch mode cursor, query parameters, query by selectable, expose execution options, and documentation (#17191)

- **Description:** Improve `SQLDatabase` adapter component to promote
code re-use, see
[suggestion](https://github.com/langchain-ai/langchain/pull/16246#pullrequestreview-1846590962).
  - **Needed by:** GH-16246
  - **Addressed to:** @baskaryan, @cbornet 

## Details
- Add `cursor` fetch mode
- Accept SQL query parameters
- Accept both `str` and SQLAlchemy selectables as query expression
- Expose `execution_options`
- Documentation page (notebook) about `SQLDatabase` [^1]
See [About
SQLDatabase](https://github.com/langchain-ai/langchain/blob/c1c7b763/docs/docs/integrations/tools/sql_database.ipynb).

[^1]: Apparently there hasn't been any yet?

---------

Co-authored-by: Andreas Motl <andreas.motl@crate.io>

libs/experimental/langchain_experimental/sql/base.py

@@ -173,7 +173,7 @@ class SQLDatabaseChain(Chain):
                 sql_cmd = checked_sql_command
 
             _run_manager.on_text("\nSQLResult: ", verbose=self.verbose)
-            _run_manager.on_text(result, color="yellow", verbose=self.verbose)
+            _run_manager.on_text(str(result), color="yellow", verbose=self.verbose)
             # If return direct, we just set the final result equal to
             # the result of the sql query result, otherwise try to get a human readable
             # final answer

libs/experimental/langchain_experimental/sql/vector_sql.py

@@ -78,6 +78,7 @@ class VectorSQLRetrieveAllOutputParser(VectorSQLOutputParser):
 
 def get_result_from_sqldb(db: SQLDatabase, cmd: str) -> Sequence[Dict[str, Any]]:
     result = db._execute(cmd, fetch="all")
+    assert isinstance(result, Sequence)
     return result